An organic light-emitting diode (OLED) is a light-emitting element using luminescent organic compounds. The OLED has a self-luminescent property, and its thinness, display quality, and power saving feature are superior to those of the liquid crystal display (LCD). Because the OLED has features of broad viewing angle, high response speed, and ultra-thinness, the OLED can be applied more widely.
As to the factors affecting the operation life of an OLED device, in addition to the luminescent organic material, inorganic indium tin oxide coating, and metal electrodes, a sealing material for blocking oxygen and moisture is also an important factor. Because the luminescent organic materials and the metal electrode are highly sensitive to oxygen and moisture, dark spots may be generated quickly on an OLED panel without appropriate protection, thus resulting in the attenuation of the light intensity and then the destruction of the entire device.
One encapsulation method is to bond the substrates by using laser to melt the frit glass. When the frit glass is melted by the laser, temperatures in central and edge portions of the frit glass are not uniform, such that only the central portions of the frit glass is completely melted and has a better bonding ability. Though the temperature in the edge portion of the frit glass can be elevated if the intensity of the laser is enhanced, so as to sinter the edge portion of the frit glass completely for enhancing the bonding effect, yet bubbles will be formed in the central portion of the frit glass due to too high temperature, thus worsening the bonding effect. Therefore, the prior art is in a dilemma.